The goal of this proposal is to develop a miniature, microscopic resolution (less than 100 microns) annular transducer array for high frequency (40 - 50 MHz) ultrasound imaging. The miniature array would be mounted on the end of a pencil shaped probe or catheter for imaging during minimally invasive surgery. The resulting real time images of subsurface tissue structures would enable a surgeon to look before cutting and would be very useful for guiding and assessing the surgery. The array will be built using a novel fabrication process based on a piezoelectric polymer instead of the traditional piezoelectric ceramic materials.